156 



NEW ENGLAND 1 ARMEK, 



Dec. •-, 18^8. " 



FOR THE NKW KNGLiND FARMER. 



CONTRIBUTIONS TO ESTOMOLOGY. 



No. V. 



Familij Djliscidn. 

 In ordei- to distingiiisli our frieinla from our eii- 

 Giiiies, iii.--,ects dccidiiilly iujurious rroiii tlioai; tliat 

 are beiioiicial to niuiikiiul, wo riiii.st study the liis- 

 tory of nil wliich may be observed, whetlier iidia- 

 iiitauts of the uir, the earth, or the water. The 

 hisects of this fanjily pass the first and last stages 

 of their e.\istence in lakes, ponds and pools. They 

 are among those that make reparation for the in- 

 juries they commit in some respects, by keeping 

 within bounds other annoying insects. In the lar- 

 va and perfect states they are predacoous, san- 

 guinary, and carnivorous. Then- food is aquatic 

 animals, such as the young fry of fish, tadpoles, 

 some of the moUusca, Crustacea, and wontis, and 

 the larvEE of dragon-flies, gnats, and mosquitoes : 

 and in their turn they serve as nourishment to 

 fishes, &c. The larvK live in the water only, the 

 pupa" are terrestrial, and the perfect insects am- 

 phibious. 1 have repeatedly found the latter re- 

 mote from water, where tliey had transported 

 'themselves by flight. It is at night that they usu- 

 ally ascend into the air, to exercise their ample 

 wings, or to seek for a better supply of food in 

 more distant waters. They sometimes enter our 

 windows in the evening, being attracted by the 

 lights. The perfect insect swims with celerity by 

 means of its feet, particularly the hind ones which 

 are flattened and densely fringed with hairs: it 

 rises from the bottom without effort in conse- 

 quence of being rather lighter than the water. 



The respiration of these insects is worth exam- ' 

 mation. In terrestrial animals of the higher clas- 

 ses air is inhaled through the throat into the] 

 lungs, where it produces an essemial and vital 

 change upon .the blood. In i\f\ws the same effect 

 Ls produced by the water, which always contains 

 a large proportion of air nfixed with it, and which, 

 entering by tlie mouth, passes out agani at the 

 gills, a kind of lungs. Other aquatic animals have 

 these gills, or branchia; as they are called, outside 

 of the body, and hence constantly bathed in wa- 

 ter, and exposed to the action of the air that it i 

 contains. Some aquatic larvaj of insects have ! 

 similar respiratory branchia;, and these are the j 

 only ones to which pure or unmixed air is not | 

 necessary. The majority of insects, in all stages, ', 

 breathe air through lateral pores or spiracles, none 

 receive it through the mouth, and the lungs are 

 replaced by longitudinal tuix.'s, their numerous i 

 minute branches, and air vesicles. The sinracles 

 of insects, vviiich open directly into the longitncli- 

 nal tubes, are from two to eivhteen in number : 

 through the posterior or anal and abdominal ones 

 the air is adnfitted or inspired, and it is expelled 

 or expired through the anterior ones or those of 

 the trunk. The Dijtisd, in the perfect state, have 

 ei"hteen spiracles, the abdominal pairs are situat- 

 ed upon the dorsum, and are covered by the ely- 

 tra. When it becomes necessary for the insect 

 to take breath it ascends to the surface of the 

 water, reversed, the under side of the tail being 

 uppermost, and the body kcjH steady by means of 

 the long oar-like hind legs, which are extended at 

 a right angle with lite trunk. The abdomen is 

 then slightly cmved so as to separate it from the 

 elytra, and elevate it above the wator, the air easily 

 insinuates itself into the cavity thus formed, and 

 ii inhaled at the pores, the last paii-s of which are 



larger than the rest to admit it in this position 

 with greater freedom. When inspiration is com- 

 pleted the elytra are quickly closed upon the body, 

 and the entrance of water, effectually prevented. 

 This motion is sometimes so sudden as to retain, 

 between the body and elytra, a small quantity of 

 unimbibed air, which makes its way under the 

 tips of the latter, where, as the insect sinks, it ad- 

 heres, a transparent globule, brilliant as quicksil- 

 ver. The npi>er surface of the body being arched 

 or convex, and its under side braced by a breast- 

 bone of several pieces firmly interlocked, it is ren- 

 dered sufficiently strong and inflexible ; while its 

 oblong oval form and thin margins are well adapt- 

 ed for its rapid and varied motions. 



Although insects have no organs of voice most 

 of them emit various sounds ; and those of tliis 

 family, in connnon with many others, exhibit their 

 distress on being handled by a creaking sound 

 produced by the friction of the tail against the 

 elytra. 



Thev pass the winter in the perfect state, bur- 

 rowing" in the banks and mud of their pools. ^ 

 One has been kept for three years and a half 

 in perfect health, in a glass vessel filled with wa- 

 ter, ami supported by morsels of raw meat. It 

 was capable of fasting a month ; was very sensi- 

 ble of the changes of the weather, which it indi- 

 cated by the height at which it remamed- in the 

 vessel. 



DeGeer fed one upon flies and spiders, and, 

 after it had lived a long time, he gave it a large 

 leech which it attacked and devoured ; but it paid 

 dear for its gluttony ; the food proving indigesti- 

 ble, was thrown up the next day with great ctTbrts, 

 and shortly afterwards the insect died. 



GE?fUS DYTISCUS. 



D. Y''"''^''^^^^- P^'i'ctured ; beneath black ; tho- 

 rax with a yellowish band and margin ; coleoptra 

 arcuato-fiisciate behind ; elytra of the female sul-| 



cated. 



Length about eleven twentieths, breadth be- 

 tween six and seven twentieths of an inch. 



Body depressed, with numerous somewhat di- 

 lated punctures. Head pale rufous, black at base, 

 with two hmated piceous spots hetween the eyes. 

 Thorax with an ochrsous yellow margin, and 

 i transverse band, which is dilated backwards al 

 I the sides, and separated from the posterior umr\ 

 Igin by an (.bsolete blackish line. Scutel imi)uno. 

 Uured", black. Coleoptra blackish from numerou^ 

 confluent, black spots and fiexnous lines ; epipleuv 

 '. ra, external margin, snbsntnral line, common an 

 ' cuated band behind the middle, and obsolete mm 

 cula at tip pale ochreous yellow. (Male with tbur 

 i obsolete elevated lines on each elytron.) Proster- j 

 Inumand anterior legs pale ochreous ; hind legs 

 piceous, thiahs black. Ventral segments with a 

 pale jnceous submargin, and, on each side, a yel- 

 lowish spot. 



Female. Coleoptra with eight, dilated, liairy 

 grooves ; (not including the external, depressed 

 submargin which is not, properly, a groove:) Iiairs 

 depressed. The external groove commences at 

 about one quarter of the length of the elytron Irnn 

 1 the base, the next to it is considerably longei-, die 

 third from the margin is shorter than the second, 

 but longer than the first, and the submargiAal 

 groove is shortest of all. 



I have not the least doubt that this is the feaale 

 of the above male, which most closely resenUes 

 D. mediahis of Mr. Say. In the latter, of whic^ I 

 have seen the sexes, the body is rather less obtfise 



in front, and the elytra of the female are not sid. 

 cated, but plain like those of the male ; and proba- 

 bly belongs to HYnAiicus of Leach. 



The fratermis is entirely distinct from the sulca- 

 lus of Europe, and with it, belongs to the subge- 

 nu« ACiLius of Leach. It is described from nine 

 specimens of the male, and six of the female. 



n. *fascicoUis. Convex, impuncturod, pale tes- 

 taceous ; vertical lunule and base of the head, an- 

 terior and posterior thoracic fascice black ; elytra 

 blackish, irroratc with distinct pale yellow dots, 

 the external margin and an abbreviated subsu- 

 tural line yellowish ; a distinct dorsal series, and 

 throe others obsolete of impressed sctiferous punc- 

 tures. Thorax of the female obsoletely corrugat- 

 ed each side ; elytra smooth. 



Length eleven twentieths, breadth over six twen- 

 tieths of an inch. 



Variety. Body beneath and feet pale piceous. 

 Specimens seven. Is probably referrible to HV- 



DATICUS. 



n. * thoracictts. Pale rufo-testaceons, impunc- 

 tured, oval, and somewhat convex ; head and 

 thorax immaculate ; external margin of the elytra 

 pale testaceous, disc blackish with confluent, black 

 tortuous lines ; three dorsal scries of punctures. 

 Female with obsolete rugse on sides of the thorax: 

 elytra smooth. 



Length nine twentieths, breadth nearly three 

 tenths of an inch. 



Specimens seven. Appears to belong to hyda- 

 Ticns. 



VEGETABLE ARTICLES OF VALUE FROM 

 DENMARK. 



Coummnicaledfor the New York Farmer, by Dr gjmitt/ i. 



MitchtU. 



The distinguished savant Hoffman Bang, in a 



letter I very lately received frotn him, dated ai 



his residence in Iloflhian's Grove, writes thus : "J 



owe you many obligations for the Memoirs, &c. 



which you sent me by Mr Wheaton. It would be 



exceedingly agreeable to me that I could be use- 



jful to you "in some way. I accordingly send you 



a collection of minerals from Norway ; three 



tracts on gardening ; seeds of different sorts ol 



I garden plants, pot-herbs, and flowering vegetables. 



which, I hope, may thrive in your American soil. 



I will endeavor to forward you another collection 



in season for planting in the spring of 1S29. 1 



earnestly request your Horticultural Society will 



send me something of the like kind in exehang^^ 



I could despatch them the best sorts of fruit trc 



that we cultivate here. Supposing that a culler 



tion of the Alga-, arranged upon the system of iHr 



Lyngbye, might be agreeable to you, 1 pack up 



the acconqjanying collection of these rare inodm- 



tions of the sea." 



Among these articles are nine varieties of peas, 

 viz. the green branched pea ; the English pea 

 called Maiklut ; green pea of France ; early pea 

 of Flanders ; another early |iea called the 3Iay- 

 dolber ; Dutch early pea ; another early pea iiani- 

 e<l horn-harred, highly esteemed in the market ol 

 Copenhagen ; another Dutch pea, and the DoriiWU 

 pea. 



Ten sorts of melon seeds. 

 Ten varieties of pumpkin seeds. 

 Twelve kinds of ornamental flowers. 

 And a parcel of the Tetragonia Expansa, or 

 New Zealand Spinage. 



The cryptogamic individuals of the marine hef- 

 barium of Mr Bang, consist of one hundred and, 



