^30 



THE AGRICULTURAL NEWS. 



October 17, 1908. 







INSECT NOTES. 



Diptera. 



(Ccmtinuuil frnm last issue (if the A'jrimllinnl .V. c'.v.) 



The midges or gall gnat.s ;ire included in the 

 Cecidomyiidae, another family of Diptera with long 

 antennae. These are very small, frail insects, not often 

 seen, but a few species are pests of considerable 

 importance The most important species of the 

 Cecidomyiidae is the Hessian Hy which att.-icks wheat 

 and other cereals in America and Europe. The loss to 

 the farmers of the United States from the ravages of 

 this insect h.as been estiumted as high as .1^10,000,000 

 annually. 



In the West Iinlies this family is lepiesented l)y the red 

 maggot of the cotton [I'ltn-irhonih/lii ;io^xi/pil), ami the flower- 

 bud maggot of cotton (Contarini'i //o.v.v/y"'')- Maggots of 

 a fly also belonging to this order liave recently been found 

 living under the barlv of tlie twigs of grafted mango trees, 

 and there are probably many others at present not known. 



In the larval stage, the red maggot lives under the bark 

 of the cotton plant, the reddish colour of the maggot suggest- 

 •ing the (•onum.n name. The egg of the fly is probably 

 usually laid in some bieak or abrasion in the l)ark, but it 

 seems likely tliat the insects are able to enter the plant even 

 ■when there is no bieak in the bark. 



The egg of tlie Hower-bud maggot of the cotton is hiid 

 in the very young flowcrduids, whieli drop to the ground as 

 the larvae within become full-grown. Very soon after the 

 buds drop, the laivae k^ave them, and the pupa stage is 

 passed in the ground. This insect is found in .\n»igua, 

 where it caused "much damage to the cotton ,hning the past 



season. 



Anothci- family of ilic tnu- flics with long antennae are 

 the Chironomidae. 'I'lu' Ijcst-known nicndieis of tliis family 

 in the West ImHes arc the sand-flies (Ci-ratd/iiii/iin). Tlie 

 larvae of most species of the family are aquatic. Some of 

 them live in the mud and decaying vegetable matter at the 

 bottom of ponds or lakes ; the larvae of others, espe<'ially of 

 the sand-Hies, live under the bark of decaying liranchcs, 

 under fallen leaves, and in .sap flowing from wounded trees. 



The family I'sychodidae include a small number of 

 <lclioate flies known as moth Hies. Tiiis common name has 

 been derived from the moth-like appearance due to the broad 

 hairy wings i>( the adult insect. They are not rare in the 

 West Indies, but are seldom' seen on account of iheir small 

 size. The larvae live in runnini; water, such as drains and 

 roadside gutters. 



The largest family of the Hies willi long antennae is the 

 Tiimlidae, and this inclinlcs some of tlie largest of all the flies. 

 These insects have remarkably long leg.s, slender bodies and 

 narrow wing»i. They are eoninionly known as ' cnine Hies' 

 and ' daddy long-legs. The laivae live in the ground where 

 thelitis pleMty of moisture, and feed upon decaying vegetable 

 mattoi-, and the roots and leaves of plants. They sometimes 

 are numerous enough to be pests of consideralilc imiiortance. 

 and in Knyland they are known as ' leather jack.-ts.' 



The flies with short antennae include man}- spccie.s, which 



from their size or habits are more fiei|uently observed than 

 most of those alrciidy referred to. The family Tabanidae 

 includes a large number of species of so-called horse-Hies, gad- 

 Hies and others. They are fairly large insects with thick 

 liodies, and many of them are capable of inflicting painful 

 bites. The adult females, which are blood-sitcking in their 

 habit, attack man and beast, while the males feed upon the 

 nectar of flowers. 



The Rot Hies'yOf'.s^r/V/di ) are bt-tter known from their 

 attacks on domestic animals, in the larval condition, than 

 from the appearance of the ;idult fly. The horse-bot 

 ((r(istroji/ii/us )'i/in) "^infests the stomach and intestines of 

 horses. The female fly attaches the eggs to the hair on the 

 shoulders or legs or belly of the horse. They are licked oti' 

 by the horse, and swallowed, and when they hatch in the 

 stomach or mouth" of the horse the larvae attach them- 

 selves to the lining of the .stomach. 



When a large number of bot larvae are attached in this 

 way to the stomach lining, serious injury is done to the animal. 

 When the larvae become full-grown they release their hold 

 ami are carried out with the excrement to the ground, where 

 they pupate. 



The larvae of the bot Hies of cattle (Hi/jxidenn'i //oris) 

 are found in small tumours under the skin. They differ 

 from the horse-bot in that upon the hatching of the eggs 

 which have been swallowed by the host animal, the larvae 

 burrow through the tissues of the body, and finally come to 

 rest just under the skin along the back. When a maggot 

 becomes full-grown, it gnaws through the .skin and falls to 

 the ground to pupate. 



The hides of cattle which have been badly attacked by 

 bot flies are almost valueless on account of the |)unctures 

 made by the escaping maggots. The amount of loss from 

 this cause in the United States has been estimated to be as 

 nnich as .■?.")( 1, 000, WK) annually. 



Another species of this grou|) attacks slieeii, the larvae 

 living in the nasal passages, and sometimes penetrating to 

 the brain, thus causing the death of the sheep. Other species 

 of this family are recorded as attacking man in tropical 

 America, the larva being found under the skin of the iiatient. 



The family Syrphidae or flower-flies is one of the 

 largest of the families of Dii)tera, al)Out 2, .500 species being 

 known. Many of the flower-flies resemble bees and wasps in 

 appeai'ance, and theyfeed i+n the nectar and pollen of flowers. 

 The larvae vary greatly in their habitat and feeding habits, 

 l)ut a few are to be found on leaves of plants, and they prey 

 on plant lice and .scale insects. 



The so called '"rat-tail maggots' are the larvae of flies of 

 this family. They 'live in stagnant water or slime and are 

 peculiar in having the hinder end of the body elongated like 

 a sleud(!r tail. This projection serves as a breathing tube 

 and jiifijects upward to the air while the body of tlie insect 

 remains in the water. The air is taken in through an aper- 

 tiiie at the tip of the tail. 



(7'ii 1,1 niiiil ml, 'I HI ill' II, rt ixsilr.) 



Destructive Insects in Ceylon. Among the 



chief jioints dealt with in the report for 1907-8 of the 

 (iovernment Kntoniologist of Ceylon are the rapid increase 

 in numbers of the Hed I'alm weevil (Khi/nrnphonis xii/nnti- 

 r„llls\ which occurred after the destruction of cocoa-nut 

 groves in certain parts by a cyclone, and the threatened 

 fncrease <if the Khinoceros beetle (Ori/cfcx r/iiiioceni.i) which 

 also attacks the co.oa-nut, and though iio.ssibly doing little 

 direct damage, facilitates the entrance of the red weevil. 



