Anthidium maculosum is a species of bee in the family Megachilidae, the leaf-cutter, carder, or mason bees. It is a solitary bee where the males are territorial and the females take part in polyandry. The males of A. maculosum differ from most other males of bee species because the males are significantly larger than females. In addition, subordinate males that act as satellites are smaller than territory-owning males. This species can be found predominately in Mexico and the United States.
Taxonomy and phylogeny
A. maculosum belongs to the subfamily Megachilinae within the hymenopteran family Megachilidae. Megachilinae is divided into 5 tribes: Anthidiini, Dioxyini, Lithurgini, Megachilini, and Osmiini. The genus Anthidium, composed of carder bees, has 92 species of bees. Anthidium is part of the tribe Anthidiini, which is one of the most diverse genera of the family Megachilidae.
Distribution
The distribution of A. maculosum ranges in Middle America and North America. These bees are most commonly found in Mexico and the United States.
Description and identification
The middle tibia of A. maculosum shows apical spines. Body sizes of these bees seem to correlate with head-widths. Therefore, a bigger head is correlated with a bigger body size. The body sizes of territorial and non-territorial bees are different. Territorial males have larger body sizes and thus correlate with holding territory, while the non-territorial bees are smaller. This smaller size is indicative of them being subordinate. In addition, males are larger than females, which is common in the family Megachilidae. However, this is rare in other bee families where the female is normally larger than the drone or male. A. maculosum nests are built in holes excavated in wood.
Colony cycle
Female solitary bees lay their eggs continuously during the breeding season. They deposit their eggs right before they close their brood cells. These carder bees are diurnal and are active only when the temperatures are above freezing. Moreover, these bees are most active when there are plenty of resources such as flowers, from which they can extract pollen and nectar.
Being solitary bees, this species does not build colonies or store honey. Generally, these bees live for around a year. Most of this time is spent in the nest until they become adults where they are seen outside the nest for three to four weeks. Prior to its adult stage, this solitary bee goes through the stages of being an egg until it progresses to the larva stage and afterward the pupa stage in the brood cell.
Diet
The females of A. maculosum collect pollen and nectar from Monarda pectinata, a flowering mint plant. Therefore, males aggregate and hold territory around these resources to ensure they copulate. This species of bee also lands on Monarda austromontana. Other plants that A. maculosum have been seen to collect pollen and nectar from in the United States include Ballota pseudodictamnus, Salvia chamaedryoides, and Salvia chamaedryoides.
Foraging behavior
Females forage in multiple territories. Foraging males will try to mate with them, and females will normally allow males to do this even though it may be at a cost because they normally get enough sperm after one mating. Multiple copulations may be costly, but females allow for them because it takes more time to resist than to let it happen. Time will be wasted trying to look for unguarded flowers that are of low quality and are rare. This extra time acquired from submitting is used to forage for their brood provisions. Females normally forage in areas that are held by males because of clumped resource distribution, since it is hard for a female to find the resources she needs otherwise. This food that the female gathers is for her progeny.
Territorial behavior
The males of A. maculosum drive out all flower-visiting insects except for conspecific females. However, if the female refuses to copulate with the male, they too will be driven out. A. maculosum can expect an intruder every 3–4 minutes. As a result, they are constantly defending their territories but not to an unmanageable degree. They spend most of their day flying around their territory making sure it is not being invaded by intruders. If they come across an intruder, both insects will clash and occasionally grapple.