Proboscis Length Research Articles

Estimating Proboscis Length from Wing Length in Bumblebees (Bombus spp.)1

Length of the fully extended proboscis and length of the entire wing are closely correlated in 4 species of bumblebees found in the northeastern U.S.A. [ Bombus fervidus (F.), B. ternarius Say, B. terricola Kirby, B. vagans Smith]. Wing length of live, though inactive, specimens can be measured accurately. Thus, it is possible to obtain accurate estimates of proboscis length, an important determinant of foraging behavior, in freeranging populations of bumblebees.

The Use of the Labial Palpus as a Measure of Proboscis Length in Worker HoneybeesApis Mellifera LigusticaandApis Cerana Cerana

SummaryIt is shown that measurement of the labial palpus can give a useful estimate of proboscis length; correlation coefficients are given for bees of both species. Differences between the two species for all measurements of proboscis parts were highly significant. For measurements that were closely correlated with the length of labial palpus, differences between two colonies of the same species (and race) were also highly significant. Other conclusions are drawn from the results about the relative lengths of parts of the proboscis.

Arhythmorhynchus capellae sp. n. (Polymorphidae: Acanthocephala), a Parasite of the Common Snipe Capella gallinago delicata

Arhythmorhynchus capellae sp. n. is described. The description is based on seven males and seven females from the Common Snipe in northern Colorado. The species is contrasted with two similar species, A. comptus Van Cleave and Rausch, 1950 and A. eroliae (Yamaguti, 1939) Van Cleave and Rausch, 1950. It differs from the former in having 14 proboscis hooks per row rather than eight or nine, and from the latter in having no bursal rays and 16 rows of 14 hooks rather than 18 rows of 12 to 13 hooks. This species is described from 14 specimens, seven males and seven females, recovered from the small intestines and ceca of six Common Snipe Capella gallinago delicata taken between January 1961 and March 1962 in northeastern Colorado. All measurements are in microns unless otherwise indicated. Arhythmorhynchus capellae sp. n. Description: Bright yellow and wrinkled when removed from gut. Trunk long and narrow with slight inflation at anterior end. Proboscis nearly cylindrical, armed with 16 longitudinal rows of 14 hooks each, 50 long and not appreciably heavier midventrally; the first three and last four hooks in each row more delicate, measuring 42 to 45 long. Neck about 350 long. Body spines extend about 1.74 mm posterior from neck, less numerous toward rear; length 30 to 35. Subcuticular nuclei restricted to narrow band at swollen area of trunk. Male: Length 12 to 41 mm (35 mm); diameter at midpoint of body 222 to 666 (494). Proboscis length 610 to 721 (653); width 144 to 200 (166). Armature same in male and female. Two testes contiguous, each about 1.43 mm long, located 1.10 to 1.30 mm behind field of body spines. Two tubular cement glands extend from area immeReceived for publication 17 September 1962. * Part of a thesis submitted to the Graduate School of Colorado State University in partial fulfillment of the requirements for the degree of Master of Science, March 1962, under the direction of Dr. O. W. Olsen. This investigaiton was in part supported by a training grant [PHS-2E-94 (cl)] from the Institute of Allergy and Infectious Diseases of the National Institutes of Health, U. S. Public Health Service. diately behind posterior testis and join common sperm duct posterior to Saefftigen's pouch.

Further Studies on the Food-Gathering Behaviour of Bumble Bees (Hymenoptera: Apidae)

Brian (1954) discussed the evidence in the literature concerning whether the correlation between the length of the proboscis of a bumble bee and the length of the corolla tube of the flower it visits for nectar results from learned or innate behaviour. She hesitated to accept the views of Kugler (1943), who supported the ‘learned’ hypothesis and considered that the individual bumble bee is instinctively attracted to a flower by its colour, scent, etc., but must learn which flowers are suited to its bodily build, because he had done no work on bees raised in isolation and therefore known to be without foraging experience. The work of Cumber (1949), which reported that there were differences in proboscis lengths between individuals of a species that visited different flowers and which therefore also supported the learned hypothesis, was suspect because he gave no data on corolla lengths. Hobbs et al. (1961), who recorded the food-preferences of certain of the workers, queens, and males of honey, bumble, and leaf-cutter bees on an isolated experimental field containing plots of alfalfa, red clover, alsike clover, and sweetclover, concluded that the preference exhibited by a bee was linked with the ease with which it could gather nectar from a flower. They found, as did Cumber, that differences in prolboscis-lengths between individuals of a species resulted in preferences for flowers of different corolla-tube lengths, e.g., the queens of Bombus hunti Greene (mean length of proboscis 8.7 mm.) greatly preferred red clover, whereas the workers (m.l.p. 6.3 mm.) preferred sweetclover.

The feeding mechanism of the butterfly Pieris Brassicae L

The paper gives a detailed anatomical and functional analysis of the butterfly’s proboscis. The proboscis consists of two maxillary galeae joined ventrally by exocuticular toothed hooks and dorsally by overlapping plates. Between them they form the food tube. The whole is a complex structure in which (i) flexible endocuticle and more rigid exocuticle, (ii) muscles, (iii) an internal skeleton of longitudinal septa, and (iv) haemocoelic turgidity play their part in the process of extension. Extension of the proboscis is restricted to the sagittal plane. When extended there is always a point of ventral bending at about one-third of the proboscis length. The angle of this bend is variable and the butterfly is enabled thereby to explore different food sources without movement of the body. The transverse section of a coiled proboscis shows a flat dorsal surface which becomes convex in extension. Contraction of the intrinsic primary oblique muscles of each galea pulls the dorsal and ventral walls towards each other. This sets up an internal pressure in the haemolymph which is maintained by a stipital valve. Because of the preponderance of flexible endocuticle at the junction of the outer walls of the galeae with their inner walls it also causes a transverse dorsal convexity to be imparted to the proboscis. The inner wall of the galea bounding the food tube consists of transversely placed exocuticular laminae so disposed in a lattice arrangement as to make possible easy movement of the proboscis in the sagittal plane as in coiling and extension, but to prevent lateral movement. Coiling of the proboscis is due to the elasticity of an exocuticular dorsal longitudinal bar which lies in each galea in the upper wall of the food tube. Along the proboscis in the dorsal haemolymph there are about one hundred and fifty pairs of large unicellular glands whose secretions are poured into the region of the dorsal linkage. They serve to lubricate the dorsal plates as they slide over each other in coiling and extension, and possibly to seal up the dorsal part of the food tube when the proboscis is extended. As a result of examining the proboscis structure and its movements, and from numerous operations involving nerve sections and perforations of the haemocoele, it is concluded that all existing theories on proboscis extension must be rejected. Extension is not caused by inflation, nor by direct muscle action, nor by elasticity of the proboscis wall. Primary intrinsic muscles, under conditions of haemocoelic turgidity maintained by a stipital valve, have effect in producing a transverse dorsal convexity of the proboscis. Extension is a consequence of this dorsal convexity in an elastic system and only indirectly of the contraction of intrinsic muscles. Assisting in the production of this changed shape of the proboscis as seen in transverse section, are (i) the longitudinal internal septa which control the degree of movement of the proboscis walls and (ii) the strong wall of the food tube which acts as a fulcrum on which the movements of the outer galea wall are made. At the point of ventral bending in the extended proboscis there is a secondary set of intrinsic oblique muscles in each galea which work antagonistically to the primaries and so prevent full extension here. The pharyngeal sucking pump is described.

イボニシのマガキ稚貝に對する加害機構について

The present paper includes the results of my work on the injuring mechanisms of Purpura clavigera of 32mm in mean height to young oysters of 15mm in mean height in a summer month from August 7th to September 7th, 1947, at Mangokuura, Miyagi Prefecture. An oyster drill can kill 40% of 60 young oysters in a summer month and an oyster about in a day. Drills injure oysters to death by boring a hole always on the right valve of oyster in 3 manners of attack; thus the penetrated hole, the non-penetrated hole on the valve and the edge of valve is encroached semicircularly. Oysters were all killed by these 3 manners of attack. Drills seem not to select the peculiar part of oyster because every part of.right valve is attacked (Fig. 1). But the holes bored are by far the most abundant at the peripheral part of valve. The definite relationship between the situation of hole and the size of oyster and drill is unrecognizable, but there is a tendency that the larger the individuals are, the more frequently oysters are bored at their periphery and that the smaller the individuals are, the much more oysters are killed by the drills. The situation of hole on the valve of oyster seems to be determined by the size of oyster drill, the place and the direction of attack and the length of proboscis of drill. A single oyster has always a single hole on the valve and no more than 2 holes. The penetrated hole is inverted conical in shape with the outer hole being always larger than the inner hole. A greater part of holes are nearly circular or elliptical in outline. The major axes of outer and inner holes are in line with or parallel with each other or nearly so. The outer and inner holes are measured 1, 3mm and 1mm respectively on an average in their major axes. The minor axis of inner hole is about 3 times as wide as the width of radula. The larger drill can usually bore the larger hole than smaller drill can do. Drills move the proboscis back and forth from the gently inclining slope towards the steep slope of inner surface of hole in sliding right and left by width of radula as they bore a hole on the valve. The inclining angle of inner surface of hole ranges about from 45° to 50° when the inner hole is situated nearly in the central part of the outer hole. We can judge the position and direction of attack, the poise of drill from the features characteristic of the hole because the drill seems usually not to shift the position, the poise of body and the movement of proboscis during the time of boring hole on the oyster. A central tooth has a large central cusp at the middle, a small lateral cusp on both sides of it and 3 to 8 marginal denticles on both sides of the lateral cusp (Table 2), the base is laterally oblong in shape. A lateral tooth is sickle-shaped with broad base; the cusp tapering towards pointed tip with entire margin. The width of radula and the size of drill can be estimated from the minor axis of inner hole. Kinoshita was of the opinion that the size of hole will be determined by the distance between 2 lateral cusps of central tooth of radula and the boring speed of drill. The minor axis of inner hole ranges from 7.5 to 8 times as wide as the distance between the lateral cusps, while it is about 3 times as wide as the entire width of radula. Thus it seems adequate to consider that the entire radula will concern in boring hole. The mechanical action of radula may be recognizable.

The Third Fossil Tsetse-Fly

AMONG some fossil insects collected in the Miocene shales of Florissant, Colorado, by Mr. Geo. Wilson, and transmitted to me by Mr. F. H. Ward, I find a beautifully preserved tsetse-fly. The insect is intermediate in size between the two fossil species previously fpund (both of which may be seen in the British Museum), and is evidently distinct. It may be called Glossina veterna, n.sp., and will be best distinguished by the following measurements in millimetres: length 12.5, length of wing 10.9, length of proboscis 4.1, length and width of abdomen each 5.6. The body and legs are brown or black, the abdomen without dark bands; the wings are hyaline, faintly brownish. The scutellum has long marginal and apical bristles, exactly as in the living species. The post-alar and first dorso-central bristles are also well preserved and normal. The anterior basal cell of the wing is about 0.6 mm. broad at end, its truncate apical end is short, and the lower margin does not bulge much near the end. The abdomen is hairy, as in living species. This excellent specimen affords additional evidence for the existence of two tsetse-flies in the American Miocene, astonishing as the fact is. The new species is nearest to G. osborni, but is too large to be the female of that form.

Fertilisation of Flowers by Insects

IN reply to Mr. Swanton's letter, I have not heard of any moth from Madagascar with an exceptionally long proboscis. I think, however, I did hear of one from East Africa with a proboscis nearly the length required; but as entomologists do not usually open out and measure the length of proboscis of all the large Sphingidæ they receive, some of the required length may exist unnoticed in our public or private collections. An inquiry at the insect departments of the Natural History Museum, and also of that of the Jardin des Plantes, would perhaps afford Mr. Swanton the required information.

Fertilisation of Orchids

MR. DARWIN, in his “Fertilisation of Orchids,” speaks of a Madagascar orchid (Angræcum sesquipedale) with nectaries 11½ inches long, and supposes that these plants must be fertilised by the efforts of huge moths, with probosces capable of such expansion, to obtain the last drops of the nectar which is secreted in the lower part of these whip-like nectaries. Can any of your readers tell me whether moths of such a size are known to inhabit Madagascar? They would probably be Sphingidæ of some kind, as no other moths would combine sufficient size and length of proboscis.