A. | The Bruchidae are most closely related to the beetles in the families Cerambycidae and Chrysomelidae. The Cerambycidae usually have long or greatly developed antennae which are frequently inserted on prominences on the frons and the bodies of these beetles are usually large, elongate or oblong with parallel sides and pubescent upper surfaces. The Chrysomelidae have antennae that are moderate in length or short, which are not inserted on prominences on the frons and the body is usually glabrous above and often oval in form. Unlike the other two families, the Bruchidae are oval, compact beetles with the elytra shortened and exposing the pygidium, the antennae are ll-segmented, serrate, rarely pectinate, and the head is prolonged into a broad muzzle. | |
B. | Key to genera of Bruchidae in the New World that infest or potentially infest seeds of Prosopis. | |
1. | Hind femur not strongly swollen, with one to four spines on underside of hind femur near appex | 2 |
Hind femur strongly swollen, with a large spine followed by 10 to 12 smaller spines on underside of hind femur near apex; in seeds Tamarindus indica; Mexico, West Indies | Caryedon serratus (Olivier) | |
2. | Hind tibia with fixed spines at apex; hind coxa not twice as broad as the femur | 3 |
Hind tibia with two movable spurs at apex; hind coxa twice as broad as femur; New World | Amblycerus Thunberg | |
3. | Antennal segments 4–11 and eyes of males greatly enlarged (Figure 3) | 4 |
Antennal segments and eyes of males not or slightly enlarged (Figure 4) | 5 | |
4. | Spines and flattened areas at bases of elytral striae 3 and 4 (Figure 9), body short, short spine at apex of hind tibia (Figure 10); Argentina, Chile, Uruguay | Rhipibruchus Bridwell |
Elytral striae 3 and 4 extending to base of elytron, without spines and flattened areas at bases of elytra (Figure 8), body elongate, without spine at apex of hind tibia (Figure 11); in seeds Prosopis alba; Argentina | Pectinibruchus longiscutus Kingsolver | |
5. | Underside of hind femur with a strong spine near apex followed by one or more smaller spines | 6 |
Underside of hind femur with a small spine near apex, without smaller spines (Figure 12); Southwestern USA, northern Mexico | Neltumius Bridwell | |
6. | Abdomen elongate, hind femur not reaching apex of abdomen | 7 |
Abdomen less elongate, eyes slightly enlarged, antennae elongate and slightly expanded (Figure 4); in seeds Prosopis strombulifera; Bolivia | Acanthoscelides longescutus (Pic) | |
7. | Scutellum twice as long as broad; glabrous line on frons not expanded toward vertex; hind femur of males and females without channel on undersurface | 8 |
Scutellum square or broader than long (Figure 7); frons with glabrous area expanded toward vertex (Figure 5); hind femur of male profoundly chanelled on undersurface; North America, West Indies, Venezuela, Hawaii | Mimosestes Bridwell | |
8. | Pygidium without grooves (Figure 13); males with small pit with dense white hairs at base of first abdominal sternum (Figure 16); Argentina, Chile, Peru, Ecuador, Galapagos | Scutobruchus Kingsolver |
Pygidium of female with two grooves (Figure 14); males without small pit at base of first abdominal sternum; North America, Venezuela, Hawaii | Algarobius Bridwell |
Only one described species from each of the genera Acanthoscelides, Caryedon and Pectinibruchus feed in the seeds of Prosopis so these species can be identified by using the above Key to Genera. Species in the genus Scutobruchus can only be separated with certainty by removing the male genitalia and examining their characters. Drawings of the male genitalia of species of Scutobruchus may be found in the article by Kingsolver (1983).
C. | Keys to species of Prosopis bruchids | ||
1. | Key to species of Algarobius | ||
1. | Female with grooves in pygidium as in Figure 15; male genitalia as in Figure 1 of Kingsolver (1972); Texas, New Mexico, northern Mexico, Hawaii | bottimeri Kingsolver | |
2. | Female with grooves in pygidium as in Figure 14; male genitalia as in Figure 4 of Kingsolver (1972); North America to Venezuela | prosopis (LeConte) | |
2. | Key to species of Amblyocerus. | ||
1. | In seeds of Prosopis chilensis in Puerto Rico and the Dominican Republic | martorelli Bridwell | |
In seeds of Prosopis from Peru or Costa Rica | 2 | ||
2. | In seeds of Prosopis juliflora in Costa Rica | epsilon Kingsolver | |
In seeds of Prosopis sp. in Peru | piurae (Pierce) | ||
3. | Key to species of Mimosestes | ||
1. | Posterior margin of eyes protruding from adjacent surfaces, not merging into contour of head (Figure 6) | 2 | |
Posterior margin of eyes not protruding from adjacent surfaces, merging into contour of head (Figure 5); North America south to Costa Rica, Hawaii | amicus (Horn) | ||
2. | Pygidium orange with large hourglass-shaped dark-brown to black spot; USA to central Mexico | protractus (Horn) | |
Pygidium without large maculation as above | 3 | ||
3. | Width of eye 1.5 to 2 times wider than width of frons; lateral margins near apex of prothorax not swollen and without spines; Hawaii, Puerto Rico, Jamaica, Colombia | insularis Kingsolver & Johnson | |
Width of eye 1.2 to 1.5 times wider than width of frons; lateral margins near apex of prothorax swollen, with strong spines; North America to Brazil | nubigens (Motschulsky) | ||
4. | Key to species of Neltumius | ||
1. | Hind tibia uniformly gray; in seeds Prosopis pubescens; Southwestern USA, northern Mexico | gibbithorax (Schaeffer) | |
Hind tibia with brown band at middle of posterior margin; in seeds Prosopis velutina; Southwestern USA | arizonensis (Schaeffer) | ||
5. | Key to species of Rhipibruchus | ||
Drawings and descriptions of species of Rhipibruchus are available in Kingsolver (1982). | |||
1. | Body large, 3.6–5.4 mm in length; with no distinct pattern on pronotum, elytra or pygidium; hairs mostly gray with pronotum and elytra largely bronze; pronotum without prominent median swollen areas but with subbasal swollen areas; Argentina | oedipygus Kingsolver | |
Body large or small; usually with pattern on dorsal surface, colour mixed; pronotum with longitudinal swollen areas adjacent to midline; subbasal swollen areas prominent | 2 | ||
2. | Pronotum in lateral view with dorsal profile strongly sinuate; elytra without strongly contrasting pattern; pygidium with short, narrow, white basal triangle and small tuft of white hairs on either side at basal 1/3; Argentina | rugicollis Kingsolver | |
Pronotum in lateral aspect with dorsal profile only slightly sinuate; elytra and pygidium usually with contrasting pattern | 3 | ||
3. | Males: Antennae strongly expanded; eyes narrowly separated in front; pygidium without sublateral depressions | 4 | |
Females: Antennae serrate; eyes more widely separated in front; pygidium with prominent sublateral depressions, often contrastingly coloured in integument and vestiture | 7 | ||
4. | Pygidium with integument uniformly dark brown to black with at most a narrow reddish yellow stripe from middle of disk to apex, vestiture sparse, evenly distributed; Argentina | psephenopygus Kingsolver | |
Pygidial integument with extensive yellowish to yellowish red areas, vestiture usually in dense patches | 5 | ||
5. | Pronotum mostly black with contrasting narrow, white basal patch of setae and narrow median line, rarely with cross-shaped mark in middle of disk; elytra with lateral and apical margins broadly black, median area of disk with 2–4 isolated dark spots but without large median, common discal spot, or broad, transverse band; Argentina | atratus Kingsolver | |
Pronotal disk black with flanks and cross-shaped median mark gray; elytra with margins usually mottled or streaked with longitudinal spots, median area usually with large discal spot or continuous or broken band | 6 | ||
6. | Hairs and integument of basal 1/3 of elytra yellowish, middle of elytra usually with large, common discal spot, occasionally with transverse band; Argentina, Uruguay | prosopis Kingsolver | |
Vestiture of basal 1/3 of elytra gray; middle of elytra occasionally with discontinuous transverse dark band but never with discal spot; Argentina, Chile, Uruguay | picturatus (Fähraeus) | ||
7. | Apical 1/5 of elytra largely black, occasionally with paler elongate spot on 7th interval; pygidium with strongly contrasting black sublateral depressions, these separated by median, white stripe; Argentina | atratus Kingsolver | |
Apices of elytra variegated black and yellowish brown; pygidium with contrasting spots or these obscure | 8 | ||
8. | Pygidial integument uniformly black with at most a reddish stripe from middle of pygidium to apex; sublateral spots obscure; Argentina | psephenopygus Kingsolver | |
Pygidial integument with contrasting dark sublateral spots | 9 | ||
9. | Pygidium with basal triangle and short median stripe white, remaining hairs yellowish, lateral spots piceous or black; Argentina, Uruguay | prosopis Kingsolver | |
Pygidial vestiture silvery gray, basal triangle and “eyebrow” spots above sublateral black spots appearing more intensely white than intervening areas; Argentina, Chile, Uruguay | picturatus (Fähraeus) | ||
D. | References in which taxonomic keys to species of Bruchidae which feed in Prosopis are published. | ||
Algarobius: Kingsolver, 1972 Mimosestes: Kingsolver and Johnson, 1978 Neltumius: Kingsolver, 1964 Rhipibruchus: Kingsolver, 1982 Scutobruchus:Kingsolver, 1983 | |||
E. | References to studies on the ecology of Bruchidae which feed in the seeds of Prosopis: Forister (1970); Center (1971); Swier (1974); Kingsolver, Johnson, Swier and Terán (1977); Conway (1980). In addition, current graduate students of Dr. C.D. Johnson are studying the ecology of Prosopis, their Bruchidae and their parasites in Arizona. | ||
F. | Some of the New World taxonomists who can identify Bruchidae reared from seeds of Prosopis. Please correspond with these scientists prior to sending specimens to them for identification. | ||
Dr. Clarence D. Johnson Box 5640 - Biology Northern Arizona University Flagstaff, Arizona 86011 USA. Telephone: (602) 523-2505 | |||
Dr. John M. Kingsolver Systematic Entomology Laboratory, USDA c/o U.S. National Museum, NHB 168 Washington, D.C. 20560 USA. Telephone: (202) 382-1787 | |||
Dr. Arturo Terán Departamento de Zoología Universidad Nacional de Tucumán Fundacion Miguel Lillo Miguel Lillo 205 Tucumán Argentina. |
Figure 3. Head of Rhipibruchus picturatus
Figure 4. Head of Acanthoscelides longescutus
Figure 5. Head of Mimosestes amicus
Figure 6. Head of Mimosestes insularis
Figure 7. Dorsal view of Mimosestes amicus
Figure 8. Dorsal view of Pectinibruchus longiscutus
Figure 9. Dorsal view of Rhipibruchus picturatus
Figure 10. Hind leg of Rhipibruchus picturatus
Figure 11. Hind leg of Pectinibruchus longiscutus
Figure 12. Hind leg of Neltumius arizonensis
Figure 13. Pygidium of Scutobruchus cera
Figure 14. Pygidium of Algarobius prosopis female
Figure 15. Pygidium of Algarobius bottimeri female
Figure 16. First abdominal sternum of Scutobruchus ceratioborus male, showing medial pit