The locust swarms, which even outnumber the cicadas, now have a new rival. They are the new breed of home runs that have been flying out of major league parks in multitudes never known before, cheapening the product, profaning America's game and permitting a new tribe of alleged sluggers to preen themselves in the mantle of a Mickey Mantle.

The home run was once the game's incomparable, muscular swat, the coup de grace, the fans' ultimate thrill. It was a happy hitter telling the pitcher in their unspoken language to, "Take that!"

It was the scene the fans lived for in their fantasy that perhaps, just perhaps, their favorite slugger would crush one, hit one out. Now it has become trite, a commonplace, no longer sometime thing, but an every-game occurrence, often two to an inning, and sometimes three. The other day, the Yankees and Blue Jays hit eight. It was not a doubleheader.

The lively ball?

Perish the thought, says the Rawlings Sporting Goods Co., which provides the baseballs to big league teams. It cites a recent demonstration by the Haller Testing Laboratories in Plainfield, N.J., which measured the bounce of 116 balls, and then proclaimed: "The modern batch is, if anything, a little bit deader."

At this news, Denmark's Hamlet would have been certain to murmur, "There's something rotten in Plainfield, N.J." Others could contend that the good Tooth Fairy told the Rawlings people exactly what they wanted to hear. Others would suggest that, if it looks like a lively ball and sounds like a lively ball and flies like a lively ball, it is a lively ball.

There is so much admissible evidence that the l987 baseball is a souped-up specimen, providing more bounce to the ounce than any ball ever issued to the major leagues. Slap hitters have turned bashers and are swatting balls over fences. Balls hit on the handle or on the end of the bat are going out of the park, exactly as they did on Robert Redford's patty-cake swing in the film, "The Natural," which could have used a technical adviser.

Exhibit A in rebuttal of all claims that the ball is no different is Wade Boggs of the Boston Red Sox. Boggs, a high average hitter and wonderful at managing the bat, has been a slap hitter all his career. But not this season. Early on, he decided to get into the swim and go for those home runs so easy to come by. Last season he had eight homers, total. This season, 13, already, and the season barely half over. He must have divined something, like so many others who are swinging for the fences. He's no dope.

The half-season home run totals in the American League are significant. How many more homers have been hit than last season? A whopping 222. Milwaukee, last year's weakest homer-hitting team, has upped its total by 50 percent. The Orioles? Even as a next-to-last team, they are 38 homers ahead of last year's production.

Many are wont to blame it on the horrid pitching this season, fingering the dismally high earned run averages. But that won't do as an explanation. To hold the pitching accountable is to ignore the devastating effects of the home run, a one-swing job that can produce four earned runs charged to a luckless pitcher. Nothing is so damaging to the ERA.

So lacking in novelty has the home run become that Jon Miller, the eager radio voice of the Orioles, who often tells the listener twice as much as he wants to know, made a telling comment the other night. Describing a homer hit against the Orioles, he noted, "That's a rare occurrence against this pitcher, who has allowed only 10 homers in his last 80 innings."

Only 10 homers given up in his last nine games considered worthy of comment as some kind of a pitching feat? Lefty Gomez wouldn't understand. In l938, he pitched the equivalent of 26.6 full games, allowing only three homers, still the AL record.

Boggs isn't the only one who has pounced on the 1987 version of the official baseball. Larry Sheets, an 18-homer man last year, already has hit 14; Terry Kennedy, 12 last year, already has 13. Eddie Murray, at 17, has equaled his 1986 total. Mark McGwire, Oakland's rookie first baseman, offers testimony that the ball is so juiced up that pitchers gripping the thing can hear that rabbit's heart beat. McGwire is a big fellow, dealing now in 450-foot homers. However, last year in 144 games in the minors, he hit 23 home runs. This year, in 79 major league games he has 31. Does he seem to be telling people something, like, for instance that the 1987 baseball has written on it, in addition to the league president's signature, an invitation to hit it out of the park?

Those who still insist that a lower standard of pitching is the cause of the record burst of homers are caught far off base in the case of McGwire.

What they seem to be saying is that McGwire is now facing American League pitching greatly inferior to what confronted him in Huntsville and Tacoma. Theirs is an argument to leave more than the baseball in stitches.