Supplementary Studies on Ant Larvae: Myrmicinae (Hymenoptera: Formicidae)

Abstract

-This article describes the five species of formicine larvae that have accumulated since the publication of our 1982 supplement to our 1976 monograph. The genus Aphomo myrmex has not been described previously; the other genera are Paratrechina and Dendro myrmex. Also included are references to formicine larvae in the literature. In this article we describe five species of formicine larvae that have accumulated since the publication of our 1982 supplement to our 1976 memoir. Here we give descriptions only. In a future supplement to our 1976 memoir we will prepare keys for the separation of the various taxa. We have noted recently in the literature a developing problem: the students of caste determination in ants need to be able to distinguish the larval instars. In the past we have rarely secured more than one instar in a sample, but now entomologists are sending us all available sizes of larvae, e.g., Aphomomyrmex below. We also include any references to ant larvae of the subfamily Formicinae which we have found since our 1982 publication. Tribe Formicini Genus CATAGLYPHIS Foerster Cataglyphis cursor (Fonscolombe) Cagniant, 1980: 3 instars, each described and sketched. Duration of stages given. Tribe Oecophyllini Genus OECOPHYLLA F. Smith Oecophylla longinoda (Latreille) Holldobler and Wilson, 1983: SEM's of labium showing opening of silk-glands. Oecophylla smaragdina (Fabricius) Hinton, 1951:163. The limpet-like caterpillars of Liphyra brassolis Westwood [Lepidoptera: Lycaenidae] feed upon the larvae of this ant: "the caterpillar lowers the edge of its carapace-like upper surface, and the ant larva is then consumed beneath the body. The caterpillars suck their juice out but do not chew them." Holldobler and Wilson, 1983: Colored photograph of worker using a larva as a shuttle to spin silk for the nest. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:22:18 UTC All use subject to http://about.jstor.org/terms 332 JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY Vol. 94(3) Tribe Brachymyrmecini Genus APHOMOMYRMEX Emery Profile pheidoloid but with narrowly rounded posterior end. Praesaepium lacking. Body hairs sparse. Of 2 types: (1) unbranched, smooth, with long flexuous tip; (2) short, unbranched, smooth with frayed tip. Labrum deeply bilobed; without chilo scleres. Mandible camponotoid but with the apical tooth long, slender and heavily sclerotized. Aphomomyrmex afer Emery Figs. 1-4 Description. MATURE WORKER LARVA. Length (through spiracles) about 2.6 mm. Profile pheidoloid but with narrowly rounded posterior end. Anus ventral. Spiracles small, decreasing slightly in diameter posteriorly. Body hairs sparse, uni formly distributed. Of 2 types: (1) 0.019-0.063 mm long, unbranched, smooth, with a long flexuous tip, on all somites; (2) about 0.025 mm long, few, with frayed tip, on AVIII-AX. Cranium transversely subelliptical, slightly wider than long. Antennae above midlength of cranium, each with 2 small sensilla. Head hairs few (about 30); 0.05-0.1 mm long, unbranched, smooth, widely scattered. Labrum large, nearly twice as broad as long, narrowed ventrally, deeply bilobed; anterior surface of each lobe with 2 or 3 short hairs and 1 or 2 sensilla; ventral surface spinulose, the spinules minute and in short rows; posterior surface densely spinulose, the spinules minute and in numerous rows radiating from dorsolateral angles and with 4-6 sensilla ven trally. Mandible large; camponotoid but with long slender heavily sclerotized apical tooth; anterior and posterior surfaces with a few longitudinal ridges which terminate on medial border in small projections making medial border erose. Maxilla with apex paraboloidal and with a few minute spinules in arcuate rows; palp a short peg with 5 (4 apical and 1 lateral) sensilla; galea digitiform with 2 apical sensilla. Labium with arcuate rows of minute spinules; palp a short peg with 5 (1 with a large capsule) apical sensilla; an isolated sensillum between each palp and the opening of the ser icteries, the latter a short transverse slit. Hypopharynx spinulose, the spinules minute and in numerous short transverse rows. YOUNG WORKER LARVA. Length (through spiracles) about 2 mm. Thorax curved ventrally, abdomen straight and with a round-pointed posterior end; diameter nearly uniform throughout. Body hairs sparse; 0.024-0.125 mm long, unbranched, smooth, very slender and flexuous, a few on each somite. Head large; cranium subhexagonal, about as broad as long. Antennae small. Head hairs 0.038-0.075 mm Figs. 1-4. Aphomomyrmex afer. 1. Mature worker larva. a, Head in anterior view, x 132; b, left mandible in anterior view, x 278; c, body hairs, x 400; d, larva in side view, x 22. 2. Young worker larva. a, Left mandible in anterior view, x 278; b, head in anterior view, x 132; c, larva in side view, x 22. 3. Mature sexual larva. a, Left mandible in anterior view, x 278; b, head in anterior view, x 132; c, body hairs, x 400; d, larva in side view, x 22; e, spiracle in surface view (upper) and in optical section (lower), x 834. 4. Young larvae. a, Very young sexual larva, x 22; b, type 2 body hair, x 400; c, young sexual larva, x 22. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:22:18 UTC All use subject to http://about.jstor.org/terms