Virginia Republican Rep. Paul S. Trible has collected $520,983 for his U.S. Senate race, giving him what may be an insurmountable lead in fund raising over his Democratic opponent, Lt. Gov. Richard J. Davis, who has raised only $32,465.

Trible's 16-to-1 advantage, bolstered by dozens of contributions from corporate political action committees, gave an immediate psychological boost to the GOP congressman's campaign. Davis yesterday acknowledged that he has no hopes of raising or spending as much money as his opponent in the race for the seat of retiring Sen. Harry F. Byrd Jr., an independent.

"I always knew Republicans were rich," said Davis, himself a millionaire, in an interview. "But I hope that now that people understand the predicament of my fund raising, they'll rally around the flag."

In Maryland, Democratic Sen. Paul S. Sarbanes, who has been targeted for defeat by the National Conservative Political Action Committee (NCPAC), continued to lead in fund raising over all of his potential Republican rivals. Sarbanes reported he has collected more than $800,000 and still had nearly$450,000 left in his campaign war chest on June 30.

Prince George's County Executive Lawrence J. Hogan, Sarbanes' most likely Republican foe, had spent all but about $4,000 of his $212,000 fund, according to his campaign finance report. Montgomery County businessman V. Dallas Merrell, who recently reentered the Republican primary, reported that his campaign was more than $67,000 in debt.

Virginia Democrats offered a quick explanation yesterday for the wide fund-raising discrepancy between Trible and Davis: The new report reflects activity only through June 30 -- barely three weeks after Davis, a 60-year-old mortgage banker from Portsmouth, was drafted as his party's nominee.

Trible, the Democrats said, has been busy raising money at least since January when he formally declared his candidacy. "He's been running for two years and I've been a candidate for 40 days," said Davis.

Davis, who had been reluctant to enter the race because of fears of money-raising troubles, insisted that he still hopes to meet his goal of raising $1.5 million, about $500,000 less than Trible expects to raise. Nevertheless, the reports, filed yesterday with the Federal Election Commission, were undoubtedly a sharp blow to Davis since more than half his income came from the Democratic Senatorial Campaign Committee. Davis reported no money at all from PACs, an indispensable funding source in any statewide race.

"There's a psychological effect to all this," said Trible spokesman Neil Cotiaux. "Your first impressions are in many ways the most important impression . . . I'd say his Davis' is a rather surprising figure that's certainly not going to score any points with the money people."

In Northern Virginia, the two Republican incumbents swept into the House of Representatives in the Reagan landslide continued to outraise and outspend their Democratic opponents this year. Rep. Stanford Parris has raised $292,778 for his reelection, according to the reports, more than twice the $133,863 collected by his 8th District Democratic challenger Herbert E. Harris. In the 10th District, Rep. Frank Wolf has raised $179,589 compared to Democrat Ira Lechner's $105,388.

The new reports underscored the dominant role that corporate and labor political action committees play in the financing of congressional campaigns. Trible's huge lead was swollen by $143,210 in PAC contributions -- a sizeable chunk of which came from defense-related industries that have benefited from Trible's promilitary stands on the House Armed Services Committee. His most recent report listed at least a dozen defense PACs, including $1,000 contributions from such firms as Martin Marietta, United Technologies, Grumman, and Rockwell International.

Trible also received hefty contributions of$1,000 or more from steel, oil, chemical and pharmaceutical PACs as well as PACs connected with the American Bankers Association and the National Automobile Dealers Association.

Aside from the Democratic committee, Davis' contributions came from 15 individual contributors, 14 of whom gave the maximum $1,000 each. They included Alexandria lobbyist William G. Thomas, Norfolk businessman Leonard Strelitz, and former state Democratic legislator Armistead L. Boothe of Alexandria, who almost defeated Byrd in a 1966 primary.

In the Maryland Senate race, the donation of nearly $200,000 by PACs to Sarbanes, much of it from labor PACs who like his liberal voting record, helped to widen the gap between him and Hogan. Hogan campaign manager Mary Hasenfus said yesterday that the gap worries her, but added that the GOP's fund raising is moving faster. Sarbanes has an advantage because he is the incumbent, she said.

Hogan, a conservative who expects support from business PACs, has drawn less than $12,000 from these sources. The largest contributor to his campaign has been the PAC run by the conservative Committee for the Survival of a Free Congress, which gave him $4,000.

Democrats, who have watched Republicans tag Sarbanes as "one of the most vulnerable senators in the country," said the figures dispute that label. "Hogan's failure to get PAC money reflects a feeling in the PAC community that Sarbanes is a strong favorite for reelection," said a staff member at the Democratic Senatorial Campaign Committee.

Hasenfus offered a different explanation, saying that PACs were reluctant to offer contributions until the candidates in the GOP primary filed for the race. "Now that the field is certain, you're going to see the business PACs come in," she said.

In the Maryland congressional races, Democratic Reps. Steny Hoyer and Michael Barnes were outdistancing their potential rivals in raising funds.

Barnes, who faces no significant primary challenge, has raised more than $160,000. Meanwhile, in what is expected to be a hard-fought Republican primary between two members of Montgomery County's fractious school board, Marian Greenblatt has raised about $25,000. Elizabeth Spencer, who joined the race after the June 30 reporting period, was not required to file an FEC report.

Hoyer, who won his House seat in a special election 13 months ago, has collected about$125,000, including a huge infusion of PAC funds in the past few weeks from a broad cross-section of business, labor and professional groups. The report of his most prominent Republican challenger, the Rev. Perry Smith III, was not available. CAPTION: Picture, LT. GOV. RICHARD J. DAVIS. . . raised $32,465 so far