COCONUTS. The most serious pests throught the islands of Zanzibar and Pemba are Oryctes monoceros and O. boas. Trees from 2 1⁄2 to 3 years old are most usually attacked, many are killed, others greatly delayed in reaching maturity. Trees in isolated positions and、on bad soil are more often attacked. Fully matured trees harbour adult beetles, but are not seriously damaged. The most useful preventive measure is the trapping of larvae in pits filled with rotting coconut trunks, vegetable debris, and a little horse manure. No insect have been found preying on the eggs, larvae, pupae or adults of the two Oryctes. The larvae are destroyed by certain mammals, including Rhynchocyon adersi, Petrodomus sultan, Pachyura murina, and two species of crows, Corvus scapulatus and C. splendens.

The following are minor pests of coconut palm:- Aspidiotus destructor, A. cyanophylli, A. lataniae, Hemichionaspis minor, Cerataphis lataniae, Rhina amplicollis, Diocalandra frumenti, Rhyncophorus phoenicis, and Termes bellicosus.

COTTON Attacked by Pectinophora (Gelechia) gossypiella, Pyroderces simplex, Earias insulana, Sylepta derogata, Prodenia litura, Acrocercops bifasciata, Bucculatrix loxoptila, Orgyia vetusta, 'Euproctis producta, Dysdercus fasciatus, D. superstitiosus, Oxycarenus albidipennis, Pseudococcus obtusus, Ps. virgatus, and Ps. citri.

CEREALS. Maize is attacked by Cirphis loreyi, Sesamia calamistis, Chilo suppressalis and Peregrinus maydis; except the last, all the other insects quoted feed also on Sorghum vulgare which is also attacked by Busseola fusca.

VEGETABLES.

Cabbages are attacked by Crocidolomia binotalis, Plutella maculipennis, Phytometra signata; egg-plants by Acanthocoris fasciculatus; Cucurbitaceae by Dacus vertebratus, D. brevistylus and D. punctatifrons; pigeon-peas (Cajanus indicus) by Pseudococcus obtusus, Tragocephala variegata, Lyprops breviusculus, Mylabris dicincta, M. amplectens, Coryna ambigua, Marasmarcha atomosa, Deudorix antalus, and Agromyza sp.; Hibiscus esculentus by Pectinophora gossypiella, Earias insulana, Sylepta derogata, Prodenia litura, and Nisotra weisei; sweet potato (Ipomoea batatas) by Cylas formicarius and Aspidomorpha punticosta; and cassava (Manihot utilissima) by Pseudococcus (Dactylopius) virgatus var. madagascariensis.

FRUIT TREES.

Citrus plants are injured by Lepidosaphes beckii, Icerya purchasi, I. seychellarum, Pseudococcus obtusus, Ps. citri, Ceroplastes rubens, Coccus viridis, Aspidiotus trilobitiformis, Cerataphis lataniae, Aphis tavaresi, Argyroploce leucotreta, Papilio demolens, Tragocephala variegata, Porphyronota maculatissima, Gyponychus cervinus, and Ceratitis capitata ; mangos by Sternochetus (Cryptorrhynchus) mangiferae, Aspidiotus (Chrysomphalus) dictyospermi, A. destructor, Pseudococcus obtusus, Lecanium adersi, L. (Saissetia) nigrum, L. (Saissetia) punctuliferum; bananas by A. destructor; and Anona muricata by Ceratitis rosa.

SHADE TREES. The African almond (Terminalia catappa, is occasionally severely attacked by bag worms (Psychidae), and less severely

MEANS

OF PREVENTION
AND CONTROL

by Miresa melanosticta; Casuarina equisetifolia by Cirina forda and Pseu dococcus obtusus; cinnamon trees by Asura saginaria; Ficus elastica by Aspidiotus (Pseudaonidia) trilobitiformis; silk cotton (Eriodendron anfractuosum) by Dysdercus superstitiosus and D. fasciatus.

TIMBER. Various woods are damaged by Macrotoma palmata, Dinoderus minutus and Termes bellicosus.

MISCELLANEOUS PLANTS. The castor plant is attacked by Thalassoides digressa, Duomitus capensis, Eutyposis impressa and Chrotogonus hemipterus; Amaryllis sp. by Brithys pancratii and Brachycerus atrox; Ipomoea sp. by Euchromia formosa; gardenias by Glyphodes sericea; roses by Mausoleopis amabilis and Aspidiotus (Chrysomphalus) aonidum; and various ornamental creepers by Pseudococcus virgatus.

STORED PRODUCTS. -The following injurious insects are mentioned:Calandra oryzae in rice, maize and sorghum; Laemophloeus pusillus in maize; Tribolium castaneum in maize and occasionally in rice; Silvanus surinamensis in maize ; Tenebriomaides uritanicus, occasional pest in maize; Bruchus chinensis, serious pest, especially of Phaseolus Mungo, and Cajanus indicus; Cossonus suturalis, occasional pest of sweet potatoes; Latheticus oryzae and Rhizopertha dominica, occasional pest of maize: Necrobia rufipes in dried copra; and Ephestia cautella in rice ard various flours.

818- Weevils Injurious to Certain Cultivated Plants in South Africa. —MARSHALL, G. A. K., in the Bulletin of Entomological Research, Vol. X, Pt. 3, pp. 273-276, pl. 1. London, April, 1920.

A description of four hitherto undescribed species of Curculionidae sent to the Imperial Bureau of Entomology from the Division of Entomology, Pretoria:

1) Protostrophus planatus, from East Rand, Transvaal, where it was recorded as injurious to the foliage of young orange trees.

2) P. noxius, from Clocolan, Orange Free State, found feeding on young wheat.

3) P. instabilis, from Nelspruit, Transvaal, also injurious to foliage of young orange trees.

4) Eremnus horticola, from Bloemfontein, Orange Free State, found feeding on dahlias and chrysanthemums.

CH. DEMAISON reports that, in the neighbourhood of Rheims, there was an apparent scarcity of insects during the year 1919. He imagines. that the continuous distribution of gas in this district evidently has some effect and he calls attention to the interest of this question from the point of view of applied entomology.

820

The Insecticidal Properties of Different Parts of Pyrethrum (Chrysanthemum cinerariaefolium).

See No. 757 of this Review.

821

Chlorochroa sayi, Grain Bug Injurious to Wheat and Other Crops in the United States. CAFFREY, D. J. and BARBER, G. W., in the Department of Agriculture, Bulletin 779, pp. 1-35 figs 13. Washington, D. C., 1919.

Since 1911, Chlorochroa sayi, Stål has caused serious damage to wheat and other crops in the inter-mountain and southwestern States. The most important damage is caused by the insect piercing the newly-formed heads of the cereals and feeding on the liquid content, which prevents the formation of the grain or greatly reduces its weight.

The reduction in yield from grain bug attack varies from 10 to 50° of the crop. In extreme cases the entire crop may be destroyed.

The cultivation of large areas formerly devoted to grazing, eliminated the native food plants of the insect and caused it to attack cultivated plants, and resulted in an increase of the pest beyond its former abundance.

Wheat, bar'ey, and rye are the cultivated crops most preferred by this bug. The species also feeds on other cereals, and on alfalfa, cotton peas, beans, cabbage, tomato, and lettuce, in addition to many wild native plants.

The first damage was recorded in 1903, and since that time serious attacks have been reported from most of the States west of the Great Plains area..

Weather and the work of parasites generally restrict destructive outbreaks in each locality to periodic intervals of two or three years.

Adults emerge from hibernation in the early spring and deposit eggs on the material composing the hibernating quarters. The resulting nymphs feed upon tender plants growing in their vicinity. Upon reaching maturity the adults migrate to cereal crops and feed upon the developing heads.

There are three distinct generations and sometimes a partial fourth generation annually. About 50 days are required to complete the life cycle of each generation. After midsummer, the numbers of the insects are greatly reduced by an egg parasite, Telenomus ashmeadi, and by two species Gymnosoma fuliginosa and Ocypterodes euchenor which parasitise the adults. Several kinds of predacious enemies contribute to the same result.

Hibernation occurs in the adult stage under weeds or rubbish. No nymphs or eggs survive the winter. Severe winters result in the death of a large number of hibernating adults and constitute one of the most important factors in restricting destructive outbreaks of this species. During normal winters, at least 95% of the adults survive when hibernating in protected places.

The most effective and practical method of control is the destruction of the adults while concentrated in their winter quarters. This is best accomplished by turning under or burning all rubbish and weeds (particularly Russian thistle, Salsola Tragus) in and about cultivated fields.

Trap crops, hand picking and hopperdozers (1) might prove practical in the control of the insect under special conditions.

(1) For the apparatus, employed in America in the control of locust attacks, see « La lutte contre les sauterelles dans les divers pays, », Inst. Internat. Agric., Rome, 1916, pp. 142143. (Ed.).

INSECTS, ETC.
INJURIOUS
TO VARIOUS
CROPS

822

Lecerfia chitinipyga n. gen., and n. sp., a Macrolepidopteron found on the Grass Aristida pungens on the Algerian Sahara. DUMONT, C. in the Bulletin de la Société entomologique de France, 1920, No. 6 pp. 102-104, figs. 1. Paris, 1920. A morphological description of the adult, larva and pupa of a Macrolepidopteron (fam. Noctuidae) found in 1919 in the Algerian Sahara (Western Grand Erg, west of El Golea), and which the writer has designated by the name of Lecerfia chitinipyga n. gen. and n. sp.

The caterpillar lives on the panicles of Aristida pungens Desf. (the "drin" of the Arabs), and eats the caryopses of that plant.

823

Insects Injurious to Cotton in Porto Rico. SMYTH, E. GRAYWOOD, in Entomological News, Vol. XXXI, No. 5, pp. 121-125. Lancaster, Pa., May, 1920. Pyroderces rileyi Wals, although frequently found, does no perceptible damage.

On the contrary, Alabama argillacea often becomes a serious menace to cotton production. As the use of arsenical insecticides is too expensive for the average cotton grower of the Island, he is advised to use a much cheaper but equally effective method of control, namely, to cut down and destroy the moth's wild food-plants growing between the cotton crops. The principal host plants of this moth are two weeds, Urena lobata and Malachra rotundifolia, both Malvaceae, the former much the more abundant and the more noxious, owing to its habit of attracting large numbers of the ant, Solenopsis germinata Fabr., because of the three small honey ducts on the underside of each leaf. Unfortunately, this weed is considered highly medicinal by the natives, and with difficulty can they be pursuaded to destroy it; if left alone, U. lobata grows vigorously. On July 15, 1916, the author was able to collect as many as 52 larvae from four plants, showing how the weed may facilitate the spread of the moth.

Dysdercus andreae L. is sometimes abundant and at other times entirely absent, so that it cannot on the whole be considered as a serious cotton pest.

An occasional larva of the cutworm, Xylomiges sunia Guen. has been seen attacking cotton foliage.

The Greenhouse thrips, Heliothrips haemorrhoidalis Burm., has done much damage according to the author, but it had not been previously reported as a cotton pest.

Another insect that is very common, and infests probably 30% of the cotton bolls, is the mealybug, Pseudococcus virgatus (Ck11.), which occurs in all stages of its development. It is believed that this beetle is heavily parasitised by a Cecidomyid, probably Karschomyia cocci Felt.

A very few specimens of Ps. citri (Risso), one specimen of Ps. longi spinus (Targ.) and a number of adults of a beetle very analagous to Coccus mangiferae (Green) were also found on the bolls.

Leaves of the Malvaceae have been occasionally found to be attacked by the lace-bug, Corythuca gossypii F.

More important than the last mentioned species is the cotton aphis, Aphis gossypii Glov., although the attack is light and scattered, thanks to the activity of its natural enemies, amongst which may be quoted, in

order of importance, Cycloneda sanguinea L., Scymnus roseicollis Muls., Acrostalagmus albus, a Braconid, a Chalcidid, a Chrysopid, and a species of Hyperaspis. In very wet weather, A. albus usually becomes the most efficient of the parasites. C. sanguinea is greatly hampered in its multiplication by the attack of a hyperparasite (Homalotylus sp).

The adults of Diabrotica graminea Balz. are often seen eating cotton blossoms or foliage, and the larvae doubtless attack the roots.

Occasional nymphs and adults of the species Empoasca have been found on foliage and bolls.

Two adults of Antianthe expansa (Germ.), one adult of the species Agallia, and a few adults of Oliaris sp. have been found on cotton

stems.

The nymphs of the green bug Nezara viridula (Linn.) were noticed for the first time in 1919 on many cotton bolls.

Lepidopterous larvae of small size have been found also on the bolls; none of them, however, resemble the treacherous pink bollworm (Pectinophora (Gelechia) gossypiella Saund.

824 - Strategus quadrifoveatus, a Coleoptoron Injurious to the Coco Palm in Porto Rico. CRESPO, M. A., in Revista de Agricultura de Puerto Rico, Vol. IV, No. 3, pp. 47-48. San Juan, P. R., 1920.

Strategus quadrifoveatus (“escarabajo rinoceronte ") is, at the present time, causing much havoc among young coconut palms in the island of Porto Rico. During the day, the adult beetle lies hidden in the soil surrounding the stem of the palms. The larvae are found hiding in the dead palms, on which they live, or in dry or rotten stakes, etc.

The insect undergoes complete metamorphosis, its life cycle lasting from twelve to thirteen months.

S. quadrifoveatus injuries the coco-palm by excavating a deep gallery in the stem while it is still young. The author has seen eight of these insects round a coco-palm a year and a half old, which was almost completely destroyed by the attacks of the pest. It has often been observed that sugar-canes growing in the neighbourhood of young coco-palms have also been injured.

The best way of killing these beetles is to attract them into piles of dry rotten stakes, heaps of coco-nut debris, or any similar places where they can find food. These traps should be visited at least once a month and the larvae destroyed.

When young coco-palms are attacked by S. quadrifoveatus, the leaves turn yellow, cease growing, and the plant finally dies. It is a good plan to dig round the palms to a certain depth, as soon as there is any suspicion of their having been infected.

All the beetles found must be collected and killed by sprinkling them with paraffin or paraffin emulsion. Further, all rubbish that might serve as a hiding-place for the insect must be removed from the plantation.