CO885-(20-21) — Page 120

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TSETSE FLIES.

SOME OF THE POINTS ON WHICH OBSERVATIONS ARE WANTED.

1. Locality.-Name of colony and nearest station, river,

Jake, &c.

(It is not possible in England to identify native villages.)

2. Where caught.-On road, at ford, in village, close to village,

far from human habitation, on railway, &c.

3. Aititule, if kuown.

4. Time of day.—(If caught at night, ? moonlight.)

5. Nature of country.-River bauk, grassy plain, dense forest,

thorny scrub, &c.

6. Presence or absence of water.

7. Diy or wet season.-(State whether the grass or scrub is

burned in the dry season.)

8. Presence of more than one species.(This is easily overlooked

as some species bear a close resemblance.)

9. Number of fly.-(Half a dozen, numerous, very numerous,

swarms, &c.)

10. Ratio of the sexes.-Males usually outnumber females.)

11. Do the flies bite through clothes?

12. Have you observed any bird or insert preying on the flies?

13. Do the flies go to the water to drink?

14. Are cattle, sheep, goats, or horses kept in the fly region?

15. Presence or absence of sleeping sickness.

Observations carried on month after month at one spot are of more value than spasmodic research in diverse districts.

DIRECTIONS FOR COLLECTING AND PRESERVING COLEOPTERA (BEETLES).

COLLECTING.-Beetles are generally of ubiquitous occurrence in the Tropics, and may be found on flowers, under bark, in rotton wood, in decaying animal and vegetable matter, in water, under stones, under moist dead leaves, in fungi, at the roots of grass (especially in damp places), in the nests of ants and termites, &c. Large numbers may be obtained by sweeping herbage and by beating branches of trees over a large net.

Many destructive chafers (Melolonthidae and Rutelidae) are noc- turnal, and may be found at dusk on flowers, or flying in swarms round trees and bushes; they may also be attracted by light. Destructive nocturnal ground-boetles may be captured in numbers by digging trenches, with the sides clean-cut and sloping, so as to prevent escape.

In sandy places a tin sunk flush with the ground, will often serve as a useful trap. When firewood is being chopped

(11-69-2.) Wt. 23967-377. 10. 12:09. D&S.

PUBLIC RECORD OFFICE

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C.O.

885

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up various destructive species may be found, both under the bark and in the wood itself; and many wood-boring species may be easily obtained flying round wood stacks at sunset.

KILLING.—The cyanide-bottle generally affords the most con- venient means for killing beetles, but most of the larger species (and especially the big weevils) must be left in it for from 6 to 12 hours; or else, on the return home, they may be transferred to boiling water, except those that are hairy, or covered with removable powdering. The smaller species may be collected alive in the Coleoptera bottles, and killed in boiling water. They should not be allowed to soak, but should be taken out after a minute or two and placed on blotting paper, so that all the moisture is removed before they are packed.

PACKING. For packing beetles, willow chip-boxes or empty match-boxes are most useful. A stock of properly prepared saw- dust mixed with flake naphthaline should be kept in a tin, and a layer of this should be placed in the bottom of the chip-box and sprinkled with a little creosote; then a layer of beetles should be placed on it, then another layer of sawdust, and so on. When the box is full, put on the lid and tap the bottom smartly; it will be found that the sawdust has settled down considerably; enough should then be added to fill the box again, and the operation should be repeated two or three times.

The data may then be written on the outside of the lid of the chip-box. When a match-box is used, the data should be written on a slip of paper of the size of the box and laid on the top of the sawdust; this slip is necessary in order that the box may be closed when full without ruckling up the contents. If specimens with different data are being packed in the same box, the different sets should be separated by slips of paper of the same size as the box; on these slips the data should be written, and the data-slip should always be above the specimens to which it refers.

The small boxes should then be packed in a strong wooden box or small biscuit tin. This should be itself wrapped with a good padding of cotton wool to avoid breakage during transit through the post. If cotton wool or wild cotton be unobtainable, a service- able padding may be made by wrapping dry moss or even grass in sheets of newspaper. Much valuable material has been destroyed in the past simply for lack of a little reasonable care in the packing. Another convenient method of packing consists in the use of paper tubes. These are made by wrapping slips of paper round a cylindrical piece of wood, or even the finger, and closing one end by folding in the edges. The beetles are then inserted from the open end, the crevices filled with sawdust (or the contents may be fixed by a wad of soft paper) and the end closed up by folding the edges. The data can be written outside the tube. This method is useful for species with long antennae, which are otherwise liable to get broken; for specimens taken paired, which may thus be packed together, and the fact noted on the cover; and finally, for examples to which it is necessary to attach a number corresponding to the notes and observations made on their habits, &c.

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In using tins for insects, it is advisable to leave them, open frequently, in order that the contents shall have an opportunity of getting thoroughly dried, otherwise beetles are apt to rot and drop to pieces.

SCALE INSECTS AND MEALY BUGS (COCCIDIA).

This remarkable family of the Homoptera is closely related to the plant-lice (Aphidae) and the powder-winged flies (Aleyrodidae). It includes some of the most destructive insects with which the agriculturist has to deal. Their chief characteristics are:-

(a.) The females are destitute of wings; legs and antennae either present or absent; mouth formed for sucking up the juices of the food-plant.

(b.) The males usually possess one pair of wings, but a few are apterous. The mouth, in all cases, is obsolete, its position being idicated by one or two pairs of ocelli, or simple eyes.

(c.) The larvae are active and "mite-like," but are furnished

with three pairs of legs.

FEMALES.

1. A large number of species protect their bodies with a secrc- tion formed of white or pinkish wax, which may assume a more or less homogeneous mass, or resemble a minature tortoise (Ceroplastes spp.; or have the covering arranged in lamellae (Orthe,iu spp.).

2. Others have the whole surface of the body covered with a thin coating of white meal-like wax, with or without white mar- ginal appendages, finally enveloping themselves in loose flocculent material, eg., Mealy-Ings (Dactylopius spp.), Cochineal insects (Cuceus cacti), Monophlebus, &c.

3. Covered with a thick resinous layer, as in the "lac insect" of commerce, Tachardia spp.

4. Covered with a separate shield of secretion of a tough horny or closely felted matter, varying from a circular to a mussel-shaped form (Diaspinae).

5. Naked, generally of varying shades of brown or pitchy-brown to black, and either flat or hemispherical in form (Lecunium spp.), or spheroid as in Kermes.

6. Resembling the flat forms of "s" at first, but finally secreting a pad or cushion of white felted wax (ovisac) of varying lengths Pulemaria spp.

7. Living under a more or less glassy test, sometimes resting in little pits or depressions (Asterolecanium spp.).

8. A few kinds construct remarkable galls on the food-plant; though, so far as it is at present known, these insects are almost exclusively confined to Australasia,

MALES.

The scales or puparis of the males are invariably sma er than those of the females; they may be found either associated with the latter or, as is often the case are fixed upon a separate portion of the food plant. The perfect males may often be reared by placing the